Wire feeder tensioner with definitive settings

ABSTRACT

A wire feeder includes a tensioner with a discrete number of compressive force settings for applying a desired compressive force to welding wire fed through the wire feeder is provided. The tensioner includes an adjustment knob with a discrete number of detents disposed along a helical surface adjacent an inner bore of the adjustment knob. The tensioner also includes a pin extending from an end of a tensioning post located in the inner bore, the pin being configured to align with the detents of the adjustment knob. Rotation of the adjustment knob adjusts alignment of the pin among the discrete number of detents, which correspond to the discrete number of compressive force settings.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. patent applicationSer. No. 13/430,912, entitled “Wire Feeder Tensioner with DefinitiveSettings,” filed Mar. 27, 2012, which claims priority to and benefit ofU.S. Patent Application No. 61/468,844, entitled “Wirefeeder DriveTension Adjustment Knob with Definitive Settings,” filed Mar. 29, 2011,each of which is herein incorporated by reference.

BACKGROUND

The invention relates generally to welding systems and, moreparticularly, to a tension adjustment knob with discrete settings foruse in welding wire feeders.

Welding is a process that has increasingly become ubiquitous in variousindustries and applications. While such processes may be automated incertain contexts, a large number of applications continue to exist formanual welding operations. Such welding operations rely on a variety oftypes of equipment to ensure the supply of welding consumables (e.g.,wire feed, shielding gas, etc.) is provided to the weld in anappropriate amount at a desired time. For example, metal inert gas (MIG)welding typically relies on a wire feeder to ensure a proper wire feedreaches a welding torch.

Such wire feeders facilitate the feeding of welding wire from a wirespool, through a pair of drive wheels, to the welding torch at a desiredwire feed rate. A mechanism such as a tensioner may be used to lower onedrive wheel toward the other, applying a compressive force to the wirebetween the drive wheels. Such tensioners typically allow an operator tocontinuously manually adjust the compressive force applied to thewelding wire based on the type of wire used or the desired wire feedspeed. However, such continuous tensioner adjustment may permit theoperator to adjust the tensioner to apply a compressive force that ishigher or lower than the desired compressive force for the specificwelding application.

BRIEF DESCRIPTION

In an exemplary embodiment, a welding system includes a welding wirefeeder. The welding wire feeder includes a welding drive assemblyhousing, a drive wheel, a clamp arm configured to pivot at a first endabout a clamp arm joint of the welding drive assembly housing, and atensioner configured to pivot about a tensioner joint of the weldingdrive assembly housing. The drive wheel is configured to rotate withrespect to the welding drive assembly housing. The clamp arm isconfigured to transfer a compressive force from the drive wheel towelding wire fed through the welding wire feeder. The tensioner includesan adjustment knob, and rotation of the adjustment knob adjusts thecompressive force transferred from the drive wheel to the welding wireamong a discrete number of compressive force settings.

In another embodiment, a welding wire feeder includes a tensionerconfigured to pivot about a tensioner joint. The tensioner includes anadjustment knob including a discrete number of detents, a cup assemblyinto which a lower portion of the adjustment knob is disposed, a springdisposed axially between the adjustment knob and the cup assembly, and atensioning post disposed within inner bores of both the adjustment knoband the cup assembly. The tensioner joint extends through a first end ofthe tensioning post. The tensioner also includes a pin extending from asecond end of the tensioning post that is opposite the first end of thetensioning post, wherein the pin is configured to align with the detentsin the adjustment knob. Rotation of the adjustment knob adjusts acompressive force transferred from a drive wheel to welding wire among adiscrete number of compressive force settings that directly correspondto the discrete number of detents in the adjustment knob.

In a further embodiment, a welding wire tensioner includes an adjustmentknob comprising a discrete number of detents disposed along a helicalsurface adjacent an inner bore of the adjustment knob, a tensioning postdisposed within the inner bore of the adjustment knob, and a pinextending radially from an end of the tensioning post. The pin isconfigured to align with the detents of the adjustment knob, androtation of the adjustment knob adjusts alignment of the pin among thediscrete number of detents.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a block diagram of an embodiment of a welding system utilizinga wire feeder that may include a tension adjustment knob with discretesettings;

FIG. 2 is a block diagram of an embodiment of certain components of thewire feeder of FIG. 1;

FIG. 3 is a perspective view of an embodiment of certain components ofthe wire feeder of FIG. 1, including a drive assembly feeding weldingwire from a spool to a welding application;

FIG. 4 is a perspective view of an embodiment of certain wire feedercomponents of FIG. 3 upon adjusting the adjustment knob of thetensioner;

FIG. 5 is a perspective view of an embodiment of certain wire feedercomponents of FIGS. 3 and 4, having the tensioner pivoted away from theclamp arm, and the clamp arm pivoted away from the wire drive assemblyhousing;

FIG. 6 is an exploded view of an embodiment of a tensioner with anadjustment knob having a discrete number of settings;

FIG. 7 is a perspective cutaway view of an embodiment of the adjustmentknob of FIG. 6 having two detents corresponding to two discretecompressive force settings;

FIG. 8 is a perspective cutaway view of an embodiment of the tensionerof FIG. 6 showing the rotation of the adjustment knob for moving the pinaway from the first detent;

FIG. 9 is a perspective cutaway view of an embodiment of the tensionerof FIG. 8 showing the pin aligned with the second detent;

FIG. 10 is a top view of an embodiment of the tensioner of FIG. 6 havingtwo detents corresponding to two discrete compressive force settings;

FIG. 11 is a top view of an embodiment of the tensioner of FIG. 6 havingfour detents corresponding to four discrete compressive force settings;

FIG. 12 is a block diagram of an embodiment of certain components of awire feeder, including a tensioner with a mechanical actuator; and

FIG. 13 is a block diagram of an embodiment of certain components of awire feeder, including an adjustment knob having control circuitry.

DETAILED DESCRIPTION

Present embodiments are directed to welding systems having a weldingwire feeder with a tensioner for adjusting the compressive force appliedto welding wire fed through the welding wire feeder. The tensionerincludes an adjustment knob that may be rotated to adjust thecompressive force among a discrete number of compressive force settings.The tensioner may also include a spring, cup assembly, tensioning post,and pin. When the adjustment knob is rotated, the pin rides along ahelical surface formed in the adjustment knob, allowing the adjustmentknob to move relative the other tensioner components such that thespring is compressed or decompressed. Consequently, the spring may exerta force on a clamp arm of the wire feeder to increase or decrease thecompressive force on the welding wire. A discrete number of detents arelocated along the helical surface, each detent corresponding to adifferent compressive force setting. Thus, an operator may rotate theadjustment knob of the tensioner to align the pin with a desired detentto apply a desired compressive force to the welding wire.

FIG. 1 is a block diagram of an embodiment of a welding system 10 inaccordance with present techniques. The welding system 10 is designed toproduce a welding arc 12 on a work piece 14. The welding arc 12 may beof any type of weld, and may be oriented in any desired manner,including MIG, metal active gas (MAG), various waveforms, tandem setup,and so forth. The welding system 10 includes a power supply 16 that willtypically be coupled to a power source 18, such as a power grid. Otherpower sources may, of course, be utilized including generators,engine-driven power packs, and so forth. In the illustrated embodiment,a wire feeder 20 is coupled to a gas source 22 and the power source 18,and supplies welding wire 24 to a welding torch 26. The welding wire 24is fed through the welding torch 26 to the welding arc 12, molten by thewelding arc 12, and deposited on the work piece 14.

The wire feeder 20 will typically include control circuitry, illustratedgenerally by reference numeral 28, which regulates the feed of thewelding wire 24 from a spool 30, and commands the output of the powersupply 16. The spool 30 will contain a length of welding wire 24 that isconsumed during the welding operation. The welding wire 24 is advancedby a wire drive assembly 32, typically through the use of an electricmotor under control of the control circuitry 28. In addition, the workpiece 14 is coupled to the power supply 16 by a clamp 34 connected to awork cable 36 to complete an electrical circuit when the welding arc 12is established between the welding torch 26 and the work piece 14.

Placement of the welding torch 26 at a location proximate to the workpiece 14 allows electrical current, which is provided by the powersupply 16 and routed to the welding torch 26, to arc from the weldingtorch 26 to the work piece 14. As described above, this arcing completesan electrical circuit that includes the power supply 16, the weldingtorch 26, the work piece 14, and the work cable 36. Particularly, inoperation, electrical current passes from the power supply 16, to thewelding torch 26, to the work piece 14, which is typically grounded backto the power supply 16. The arcing generates a relatively large amountof heat that causes part of the work piece 14 and the filler metal ofthe welding wire 24 to transition to a molten state, thereby forming theweld.

To shield the weld area from being oxidized or contaminated duringwelding, to enhance arc performance, and to improve the resulting weld,the welding system 10 also feeds an inert shielding gas to the weldingtorch 26 from the gas source 22. It is worth noting, however, that avariety of shielding materials for protecting the weld location may beemployed in addition to, or in place of, the inert shielding gas,including active gases and particulate solids.

FIG. 2 is a block diagram of an embodiment of certain components of thewire feeder 20 of FIG. 1. As previously described, in certainembodiments, the welding wire 24 is supplied from the spool 30, whichmay be mounted via a spool mount 42 onto an inner wall 44 of the wirefeeder 20. The wire drive assembly 32 facilitates progressive feeding ofthe welding wire 24 from the spool 30 to the welding torch 26 at adesired rate for the welding application. A feed motor 46 is providedthat engages with two drive wheels 48 and 50 to push the welding wire 24from the wire feeder 20 toward the welding torch 26. In practice, one ofthe drive wheels (i.e., a driven drive wheel) 48 is mechanically coupledto the feed motor 46 and is rotated by the feed motor 46 to drive thewelding wire 24 from the wire feeder 20, while the mating wheel (i.e.,an idler drive wheel) 50 is biased toward the welding wire 24 tomaintain contact between the two drive wheels 48 and 50 and the weldingwire 24. The drive wheels 48 and 50 may be supported in a welding driveassembly housing 52, which may be attached to the inner wall 44 of thewire feeder 20. Both the driven drive wheel 48 and the idler drive wheel50 are configured to rotate with respect to the welding drive assemblyhousing 52. The illustrated embodiment shows one pair of drive wheels 48and 50, however the wire feeder 20 may include multiple pairs of suchdrive wheels in certain embodiments.

In addition to mechanical components, the wire feeder 20 also includesthe control circuitry 28 for controlling the wire feed speed of thewelding wire 24 through the wire feeder 20, among other things. Incertain embodiments, processing circuitry 54 is coupled to an operatorinterface 56 on the wire feeder 20 that allows selection of one or morewelding parameters, for example, wire feed speed. The operator interface56 may also allow for selection of such weld parameters as the weldingprocess, the type of welding wire 24 utilized, current, voltage or powersettings, and so forth. The processing circuitry 54 communicates withthe feed motor 46 via a motor drive circuit 58, allowing control of wirefeed speeds in accordance with operator selections. Additionally, theprocessing circuitry 54 permits these settings to be fed back to thepower supply 16 via interface circuitry 60 and/or stored by appropriatememory circuitry 62 for later use. The control circuitry 28 within thewire feeder 20 may also regulate the flow of shielding gas from the gassource 22 to the welding torch 26. In general, such shielding gas isprovided at the time of welding, and may be turned on immediatelypreceding welding and for a short time following welding.

FIG. 3 is a perspective view of an embodiment of certain components ofthe wire feeder 20 of FIG. 1, including the wire drive assembly 32feeding welding wire 24 from the spool 30 to a welding application. Aspreviously mentioned, the idler drive wheel 50 engages with the weldingwire 24, applying a downward force F to the welding wire 24 for feedingthe welding wire 24 between the drive wheels 48 and 50. This downwardforce F generates traction between the drive wheels 48 and 50 and thewelding wire 24, effectively holding the welding wire 24 in alignmentthrough a welding wire feed region 64 located between the drive wheels48 and 50. The welding wire feed region 64 may be defined by groovesformed along the circumference of the drive wheels 48 and 50 such thatthe welding wire 24 is held between two aligned grooves, one on each ofthe drive wheels 48 and 50. A wire inlet guide 66 may direct the weldingwire 24 from the spool 30 into the welding wire feed region 64 betweenthe drive wheels 48 and 50. As illustrated, the idler wheel 50 ismounted on a clamp arm 68, which pivots about one end 70 at a pivotpoint 72 and may be forced downward at an opposite end 74 by a tensioner76. The tensioner 76 is configured to pivot about a tensioner joint 78of the welding drive assembly housing 52 in order to secure or releasethe clamp arm 68. When the clamp arm 68 is secured, the tensioner 76 mayapply a desired amount of compressive force F to the clamp arm 68,pushing the idler drive wheel 50 toward the driven drive wheel 48.Adjustment of the compressive force F applied by the tensioner 76 mayalter the size of the welding wire feed region 64 between the grooves. Adesired compressive force F may be determined based on materialproperties of the welding wire 24 (e.g., steel versus aluminum weldingwire) and/or a desired wire feed speed.

Initial insertion of the welding wire 24 into the welding wire feedregion 64 between the drive wheels 48 and 50 may be facilitated bypivoting the clamp arm 68, with the attached idler drive wheel 50, aboutthe pivot point 72, thereby lifting the idler drive wheel 50 away fromthe driven drive wheel 48. Once the welding wire 24 is positioned asdesired between the drive wheels 48 and 50, the tensioner 76 may beengaged with the clamp arm 68, and the amount of force F placed on theclamp arm 68 by the tensioner 76 may be adjusted via an adjustment knob80 of the tensioner 76. More specifically, an operator may rotate theadjustment knob 80 to compress or release a spring in the tensioner 76,thereby increasing or decreasing the force applied to the clamp arm 68.

In accordance with present embodiments, rotation of the adjustment knob80 adjusts the compressive force F transferred from the first drivewheel 50 to the welding wire 24 among a discrete number of compressiveforce settings. Such compressive force settings may each be appropriatefor specific types of welding wire. For example, FIG. 3 illustrates theadjustment knob 80 rotated to a position for applying an appropriatecompressive force F to feed welding wire 24 that is approximately 0.035inches in diameter. This welding wire size setting may be displayed intext 82 on the adjustment knob 80 such that when the adjustment knob 80is positioned at a discrete compressive force setting for 0.035 inchdiameter welding wire, an operator may clearly see the setting displayedon the adjustment knob 80.

FIG. 4 is a perspective view of an embodiment of certain wire feedercomponents of FIG. 3 as the compressive force setting of the tensioner76 is adjusted. A rotation 84 of the adjustment knob 80 lowers theadjustment knob 80 relative to other components of the tensioner 76, asshown by arrow 88. As a result, a spring within the tensioner 76 iscompressed to increase the compressive force F delivered to the firstdrive wheel 50. This compressive force F may correspond to thecompressive force setting for 3/64 inch diameter wire, as indicated intext 90 on the adjustment knob 80. The textual indications 82 and 90 maybe located along different circumferential positions of the adjustmentknob 80, allowing a user to view the compressive force setting (based onwire diameter) to which the tensioner 76 is currently set.

FIG. 5 is a perspective view of an embodiment of certain components ofthe wire feeder 20 of FIGS. 3 and 4, having the tensioner 76 pivoted outof engagement with the clamp arm 68, and the clamp arm 68 pivoted awayfrom the welding drive assembly housing 52. The tensioner 76 is pivotedabout the tensioner joint 78, (arrow 100), and the clamp arm 68 ispivoted about its pivot point 72 (arrow 102) to lift the idler drivewheel 50 away from the driven drive wheel 48. The illustrated embodimentof the wire drive assembly 32 features a tensioner 76 configured topivot in a plane generally perpendicular to the direction 104 of thewelding wire 24 fed through the wire drive assembly 32. However, thetensioner 76 may be configured to pivot about the tensioner joint inother planes, for example, in a plane generally parallel to thedirection 104 of the welding wire 24 fed through the wire drive assembly32.

FIG. 6 is an exploded view of an embodiment of a tensioner 76 with anadjustment knob 80 having a discrete number of detents corresponding toa discrete number of compressive force settings. The tensioner 76includes the adjustment knob 80, a spring 114, a cup assembly 116(having a cup 118 and a base 120), a tensioning post 122, and a pin 124.A lower portion 126 of the adjustment knob 80 is disposed around the cupassembly 116, and the spring 114 is disposed axially, with respect to atensioner axis 128, between the adjustment knob 80 and the cup assembly116. The tensioning post 122 is disposed within an inner bore 130 of thecup assembly 116 and an inner bore 131 of the adjustment knob 80, andthe tensioning post 122 includes a tensioner aperture 132 extendingthrough a first end 134 of the tensioning post 122. The tensioneraperture 132 is configured to mate with the tensioner joint 78 of thewelding drive assembly housing 52. This allows the entire tensioner 76to pivot about the tensioner joint 78, as previously discussed. The pin124 may extend from an aperture 136 located at a second end 138 of thetensioning post 122 opposite the first end 134. The pin 124 isconfigured to align with a discrete number of detents formed in theadjustment knob 80.

Rotating the adjustment knob 80 causes the pin 124 to move relative tothe adjustment knob 80 as described in detail below. This movement ofthe pin 124 forces the tensioning post 122 to move relative to theadjustment knob 80 as well, and this moves the cup assembly 116 up ordown relative to the adjustment knob 80. As the cup assembly 116 movesupward, the spring 114 compresses, and the force of the compressedspring 114 transfers to the clamp arm 68, increasing the compressiveforce F applied to the welding wire 24 in the wire feeder 20. The spring114 has a specific spring constant relating the compression length ofthe spring 114 to the resulting spring force that increases or decreasesthe compressive force F. Therefore, the compressive force F applied bythe tensioner 76 may be varied by switching between springs 114 havingdifferent spring constants, in addition to rotating the adjustment knob80.

FIG. 7 is a perspective cutaway view of an embodiment of the adjustmentknob 80 of FIG. 6 having two detents 148 and 150 corresponding to twodiscrete compressive force settings. In addition, the adjustment knob 80includes a helical surface 152 adjacent the inner bore 131 of theadjustment knob 80, and the detents 148 and 150 are located along thehelical surface 152. The helical surface 152, including the detents 148and 150, may be molded into a surface of the inner bore 131 of theadjustment knob 80. As the adjustment knob 80 is rotated, the pin 124 ofthe tensioner 76 may travel up or down relative to the adjustment knob80, supported by the helical surface 152. When the rotation of theadjustment knob 80 stops, the pin 124 may settle into the detent 148 orthe detent 150, depending on the relative position of the pin 124 alongthe helical surface 152. That is, if an operator turns the adjustmentknob 80 to a position where the pin 124 is situated on the helicalsurface 152 between the detents 148 and 150 and the adjustment knob 80is released, the pin 124 may be forced by the spring 114 to slide orroll down the helical surface 152, coming to rest in the detent 148.However, if the operator rotates the adjustment knob 80 far enough tomove the pin 124 along the helical surface 152 and into alignment withthe second detent 150, then the detent 150 will resist downward motionof the pin 124 toward the first detent 148. In certain embodiments,another corresponding helical surface 152 may be formed in theadjustment knob 80 along a surface of the inner bore 131 that issubstantially opposite the illustrated helical surface 152 within theinner bore 131. This may allow opposite ends of the pin 124 to rest on arespective helical surface 152 of the adjustment knob 80 such that thepin 124 maintains a substantially horizontal orientation. In someembodiments, the pin 124 may be part of the tensioning post 122 thatextends to one side of the tensioning post 122 and not the other. Insuch embodiments, it may not be desirable for the helical surface 152 tobe formed in opposite sides of the adjustment knob 80.

It should be noted that the style and outward appearance of thetensioner 76 may conform to an industry standard. Indeed, the tensioner76 is configured to adjust the compressive force F applied to thewelding wire 24 through a rotation 158 of the adjustment knob 80, amethod of adjustment that may currently be familiar to weldingoperators. However, instead of offering a continuous range ofcompressive force adjustment to the operator, the tensioner 76 providesa discrete number of detents (e.g., 2, 3, 4, 5, or even more detents).This may allow the operator to switch between compressive force settingsin a relatively fast and accurate manner. In addition, the discretenumber of compressive force settings may allow for easier instructionsto be given for deciding an appropriate compressive force setting, andfor adjusting the tensioner 76 accordingly, making it less likely thatthe operator will apply an undesired compressive force.

FIGS. 8 and 9 are perspective cutaway views of an embodiment of thetensioner 76 of FIG. 6 showing the rotation 158 of the adjustment knob80 for moving the pin 124 from alignment with the first detent 148 intoalignment with the second detent 150. FIG. 8 shows the pin 124 alignedwith the first detent 148. With the tensioner 76 in this position, aspring force exerted by the spring 114 on the adjustment knob 80 maycause the adjustment knob 80 to press upward against the pin 124,thereby holding the pin 124 in the detent 148. The rotation 158 of theadjustment knob 80 about the tensioner axis 128 may be performedmanually by an operator or automatically, as discussed in detail below.Such rotation 158 causes the pin 124 to move away from the first detent148 and along the helical surface 152 of the adjustment knob 80, towardthe second detent 150. As previously mentioned, the detents 148 and 150may correspond to compressive force settings such that when the pin 124is aligned with the first detent 148, the compressive force F applied tothe clamp arm 68 of the wire feeder 20 is a known and desired amount offorce for the particular welding wire 24 and wire feed speed. That is,the tensioner 76 may be configured such that when the pin 124 iscaptured in the first detent 148, the compressive force F may be a forceappropriate for feeding welding wire 24 of a certain size (e.g., 0.035inches in diameter as shown in FIG. 3).

FIG. 9 shows the tensioner 76 having the adjustment knob 80 positionedsuch that the pin 124 is aligned with the second detent 150. Since thesecond detent 150 is located at a relatively higher position of theadjustment knob 80 than the first detent 148, the pin 124 may urge thetensioning post 122 to a relatively higher position within the innerbore 131 of the adjustment knob 80. This moves the cup assembly 116upward relative to the adjustment knob 80, compressing the spring 114.The compressed spring 114 exerts an increased spring force 160 in thedownward direction to the cup assembly 116 and the tensioning post 122.The increased spring force 160 may be transferred from the tensioner 76to the clamp arm 68 via the base 120 of the cup assembly 116, and thecompressive force F applied to the welding wire 24 is thus increased.When the pin 124 is captured in the second detent 150 as shown, thecompressive force F may be a force appropriate for feeding the weldingwire 24 of approximately 3/64 inches in diameter, as shown in FIG. 4.

An operator may rotate the adjustment knob 80 to a position such thatthe pin 124 is not aligned with either the first detent 148, as shown inFIG. 8 or the second detent 150 of FIG. 9. When the adjustment knob 80is released while the pin 124 is located along the helical surface 152between the two detents 148 and 150, the spring 114 pushes against theadjustment knob 80. This may cause the pin 124 to roll or slide alongthe helical surface 152 of the adjustment knob 80 toward the firstdetent 148. Thus, if an operator rotates the adjustment knob 80 to aposition beyond a desired compressive force setting, the tensioner 76may automatically adjust the compressive force F applied to the weldingwire 24. The illustrated helical surface 152 allows the adjustment knob80 to either lock into the relatively higher detent 150 or to rotateback to the relatively lower detent 148.

It should be noted that different arrangements of the components of thetensioner 76 may be possible. In certain embodiments, for example, thecup assembly 116 may be one solid component, instead of the separate cup118 and the base 120. In addition, the components may be any suitableconfiguration that allows the adjustment knob 80 to be moved relative tothe other components in order to adjust a downward force on thetensioning post 122 and cup assembly 116 by compressing or decompressingthe spring 114. For example, the pin and helical surface coupling may beestablished in reverse (i.e., the pin 124 extending from the adjustmentknob 80 and the helical surface 152 formed in the tensioning post 122).The helical surface 152 and pin 124 may be formed between the cupassembly 116 and the adjustment knob 80 in certain embodiments. In suchembodiments, the helical surface 152, which is shown in the illustratedembodiments as formed inside the adjustment knob 80, may be molded as anexternal feature on an outer surface of the adjustment knob 80. The cupassembly 116 may be configured to receive the adjustment knob 80 suchthat the pin 124, extending inward from the cup assembly 116, issupported on the helical surface 152.

FIG. 10 is a top view of an embodiment of the tensioner 76 of FIGS. 6-9,with the two detents 148 and 150 corresponding to two distinctcompressive force settings. In the illustrated embodiment, the pin 124is aligned with the first detent 148. The rotation 158 of the adjustmentknob 80 in a clockwise direction may bring the second detent 150 towardthe pin 124, as indicated by arrows 170. The pin 124, which is disposedin the aperture through the tensioning post 122, may roll or slide alongthe helical surface 152 as the rotation 158 brings the second detent 150toward the pin 124. When the pin 124 is aligned with the second detent150, the detent 150 holds the pin 124 as the tensioner 76 delivers anappropriate compressive force F to the welding drive assembly housing52. The rotation 158 may be reversed to return the pin 124 from thesecond detent 150 to the first detent 148, thereby reducing thecompressive force F to the previous value.

FIG. 11 is a top view of an embodiment of the tensioner 76 having fourdetents 178, 180, 182, and 184 corresponding to four distinctcompressive force settings of the wire feeder 20. Similar to FIG. 10,the rotation 158 of the adjustment knob 80 may cause the pin 124 to moverelative to the adjustment knob 80. More specifically, the pin 124 movesalong the helical surface 152 in a direction indicated by arrows 186,from the first detent 178 toward the subsequent detents 180, 182, and184. A different compressive force setting corresponds to each detent178, 180, 182, and 184, and the appropriate or desired compressive forcesetting may be determined based on a size or material of the weldingwire 24 or the wire feed speed of the wire feeder 20. Thus, thetensioner 76 may include an adjustment knob 80 having any discretenumber of detents for capturing the pin 124 in a position that providesthe desired compressive force F to the welding drive assembly housing52.

FIG. 12 is a block diagram of an embodiment of the tensioner 76 having amechanical actuator 192 for rotating the adjustment knob 80 of thetensioner 76. Indeed, the mechanical actuator 192 may rotate theadjustment knob 80 such that the pin 124 aligns with a selected detent194. This detent 194 may be determined by the control circuitry 28 ofthe welding wire feeder 20 based at least in part on welding wire typesettings 196 and/or welding wire drive feed speed settings 198 of thewelding wire feeder 20. That is, the control circuitry 28 may determinea desired compressive force setting based on welding wire type settings196 (e.g., size or material of the welding wire 24 used) and/or thespeed at which the wire drive assembly 32 is feeding the welding wire24. The selected detent 194 corresponds to the desired compressive forcesetting, as determined by the control circuitry 28, and the controlcircuitry 28 may control the mechanical actuator 192 to rotate theadjustment knob 80 such that the pin 124 aligns with the selected detent194. Thus, the tensioner 76 may automatically adjust the compressiveforce F applied to the welding wire 24 based on various settings. Incertain embodiments, the mechanical actuator 192 may not only align thepin 124 with selected discrete detents 194, but rather may determine anappropriate compressive force F along a broad spectrum of values (i.e.,as opposed to discrete settings), and adjust the rotation of theadjustment knob 80 accordingly.

The mechanical actuator 192 may include a motor coupled to theadjustment knob 80 and configured to rotate the adjustment knob 80 aboutthe tensioner axis 128, as shown by arrow 200. Since the adjustment knob80 is configured to move relative to the tensioning post 122, the pin124, and other elements of the tensioner 76, the mechanical actuator 192may be coupled to the adjustment knob 80 and not to the components ofthe tensioner 76 designed to remain stationary with respect to thetensioner axis 128. Although shown as connected to the adjustment knob80 from above, any suitable arrangement of mechanical actuator 192 maybe used to rotate the adjustment knob 80. For example, the mechanicalactuator 192 may engage the lower portion 126 of the adjustment knob 80through a geared connection to a motor coupled to the tensioner 76.

Components of the welding system 10, such as the wire feeder 20, mayinclude circuitry for determining which detent the pin 124 is alignedwith at any given moment. This circuitry may transmit a signal to thecontrol circuitry 28 of the wire feeder 20, the signal relating to thedetent with which the pin 124 is currently aligned. For example, thecircuitry may be configured to send the signal based on a position of aswitch located in the wire feeder 20. The switch, which may be locatedalong the inner wall 44 of the wire feeder 20, may be actuated by theadjustment knob 80 as it is rotated to different positions correspondingto the discrete number of detents and compressive force settings.

FIG. 13 is a block diagram illustrating another embodiment of circuitry206 configured to determine the detent with which the pin 124 iscurrently aligned. In this embodiment, the tensioner 76 includes thecircuitry 206 incorporated into the adjustment knob 80. Each of thedetents 148 and 150 of the adjustment knob 80 may include an opposingpair of leads 208 and 210, respectively. The leads 208 and 210 may beconnected through control lines 212 and 214 leading to the circuitry206. When the pin 124 is aligned with the detent 148, as illustrated,the pin 124 may contact the leads 208 to complete a circuit between thecircuitry 206, the leads 208, and the control lines 212. Similarly, whenthe pin 124 is aligned with the detent 150, the pin 124 may contact theleads 210 to complete a circuit between the circuitry 206, the leads210, and the control lines 214. In other embodiments, one or moresensors may be molded into the adjustment knob 80, such that when thepin 124 aligns with a given detent, the one or more sensors send asignal to the circuitry 206. The circuitry 206 may be configured totransmit a signal 216 to the control circuitry 28 of the wire feeder 20,and the signal 216 may relate to the detent (e.g., 148) with which thepin 124 is currently aligned.

Based on the signal 216 received from the circuitry 206 of theadjustment knob 80, the control circuitry 28 of the wire feeder 20 maydisplay information on the operator interface 56. The informationdisplayed may relate to the compressive force setting that correspondsto the detent (e.g., 148) with which the pin 124 is currently aligned,as communicated via the transmitted signal 216. For example, the controlcircuitry 28 may display information on the operator interface 56 thatindicates the size and material of welding wire for which the currentcompressive force setting is appropriate (e.g., steel, aluminum, 0.35inch diameter, or 3/64 inch diameter welding wire). The controlcircuitry 28 also may display information on the operator interface 56indicative of an appropriate wire feed speed for the current compressiveforce setting, or a general numeral representative of ranges of wiretype settings in combination with wire drive feed speed settings. Thismay allow an operator to confirm that a current position of theadjustment knob 80 corresponds to the welding wire 24 used and/or thedesired welding wire drive feed speed.

In some embodiments, the control circuitry 28 may display a message onthe operator interface 56 related to a recommended compressive forcesetting and/or a recommended detent with which to align the pin 124. Therecommended setting and/or detent may be based at least in part on thewelding wire type settings 196 and/or the welding wire drive feed speedsettings 198 of the welding wire feeder 20. These various settings 196and 198 may be input or selected by an operator through the operatorinterface 56, allowing the control circuitry 28 to determine a desiredcompressive force setting and/or corresponding detent based on thesettings 196 and 198. The control circuitry 28 may also compare thedesired compressive force setting and/or detent with the currentcompressive force setting and/or the current detent 148, as determinedby the circuitry 206 in the adjustment knob 80. Thus, the controlcircuitry 28 may display a message on the operator interface 56indicating how to rotate the adjustment knob 80 to bring the pin 124into alignment with the desired detent.

In certain embodiments, the wire feeder 20 may include a tensioner 76having both the mechanical actuator 192 of FIG. 12 and the circuitry 206of FIG. 13. Such a wire feeder 20 may allow for an entirely automatedadjustment of the tensioner 76 to apply an appropriate compressive forceF to the welding wire 24. For example, the control circuitry 28 maydetermine that the desired detent is the detent 150, based on thewelding wire type settings 196 and/or wire drive feed speed settings 198input through the operator interface 56. If the pin 124 is aligned withthe detent 148, however, the circuitry 206 may transmit a signal 216that the pin 124 is currently aligned with the detent 148. In response,the control circuitry 28 may control the mechanical actuator 192 torotate the adjustment knob 80 until the pin 124 is brought intoalignment with the desired detent 150.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

1. A welding wire feeder, comprising: a tensioner configured to pivotabout a tensioner joint, wherein the tensioner comprises: an adjustmentknob comprising a discrete number of detents; a cup assembly about whicha lower portion of the adjustment knob is disposed; a spring disposedaxially between the adjustment knob and the cup assembly; a tensioningpost disposed within inner bores of both the adjustment knob and the cupassembly, wherein the tensioner joint extends through a first end of thetensioning post; and a pin extending from a second end of the tensioningpost that is opposite the first end, wherein the pin is configured toalign with the detents in the adjustment knob; wherein rotation of theadjustment knob adjusts a compressive force transferred from a drivewheel to welding wire among a discrete number of compressive forcesettings that directly correspond to the discrete number of detents inthe adjustment knob.
 2. The welding wire feeder of claim 1, wherein theadjustment knob comprises a helical surface adjacent the inner bore ofthe adjustment knob, wherein the detents are located along the helicalsurface.
 3. The welding wire feeder of claim 1, wherein the tensionercomprises a mechanical actuator for rotating the adjustment knob suchthat the pin aligns with a selected detent of the adjustment knob. 4.The welding wire feeder of claim 3, wherein the selected detent isdetermined by control circuitry based at least in part on welding wiretype settings and/or welding wire drive feed speed settings.
 5. Thewelding wire feeder of claim 1, comprising circuitry for determiningwhich detent the pin is currently aligned with, and transmitting asignal relating thereto to control circuitry.
 6. The welding wire feederof claim 5, wherein the control circuitry is configured to displayinformation on an operator interface of the welding wire feeder, whereinthe information relates to the compressive force setting thatcorresponds to the alignment of the pin with the detent based on thetransmitted signal.
 7. A welding wire tensioner, comprising: anadjustment knob comprising a discrete number of detents disposed along ahelical surface adjacent an inner bore of the adjustment knob; atensioning post disposed within the inner bore of the adjustment knob;and a pin extending radially from an end of the tensioning post, whereinthe pin is configured to align with the detents of the adjustment knob;wherein rotation of the adjustment knob adjusts alignment of the pinamong the discrete number of detents.
 8. The welding wire tensioner ofclaim 7, wherein the tensioner comprises a mechanical actuator forrotating the adjustment knob such that the pin aligns with a selecteddetent of the adjustment knob.
 9. The welding wire tensioner of claim 8,wherein the selected detent is determined by control circuitry based atleast in part on welding wire type settings and/or welding wire drivefeed speed settings.
 10. The welding wire tensioner of claim 7,comprising circuitry for determining which detent the pin is currentlyaligned with, and transmitting a signal relating thereto to controlcircuitry.